With development of a display technique, a liquid crystal display with a narrow frame structure design is getting more and more popular. The liquid crystal display can utilize a light emitting diode (briefed as LED) or a cold cathode fluorescent lamp (briefed as CCFL) as its backlight, mainly in a side-lit type and a direct-lit type. In the side-lit type backlight, a plurality of point light sources are provided in a line adjacent to one another; in a direct-lit type, the plurality of point light sources are provided regularly on a planar plane. In order to prevent an optical film sheet from moving or dropping off etc. during the handling and assembly process of the backlight, a film material fixing structure is needed to fix the optical film sheet.
It is known for the inventor that the film material is positioned in a direction perpendicular to the film material usually by a film material fixing hook, and as a film material fixing structure is added in the direction perpendicular to the film material, a width of the frame is increased. If the frame is too narrow to perform the positioning of the film material in a direction perpendicular to the film material, thus increasing the difficulty of a narrow frame design.